Arc-extinguishing device



L. N. CRICHTON.

ARC EXTINGUISHING DEVICE.

APPLICATION FILED AUG-30, I9l6.

1 ,368,325, Patented Feb. 15; 1921.

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UNITED STATES PATENT OFFICE.

LESLIE N. CRICI-ITON, OF WILKINSBURG. PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A. CORPORATION OF PENNSYL- VAN IA.

ARG-EXTINGUISHING DEVICE.

Application filed August 30. 1916.

To all whom it may concern:

Be it known that I, LESLIE N. Cmon'ron .that' shall alternately open and close a circuit interrupter to so reduce the voltage of the circuit that the arc will be extinguished without causing the apparatus connected to the circuit to fall out of synchronism.

Another object of my invention is to provide a device of the above indicated character that shall have a single relay for controlling the alternate opening and closing of the interrupter when an arc occurs on the system.

Another object of my invention is to provide a device of the above indicated character that shall have means actuated by the controlling relay for precluding the automatic opening andclosmg of the interrupter after the relay has operated a predetermined.

number of times.

Co ending application, Serial No. 83,786, filed glarch 13, 1916, by F. E. Ricketts, discloses a device for successively opening and closing a circuit interrupter in accordance with the difference in potential on the respective sides of the interrupter and means for precluding the closing of the interrupter after the arc has existed for a predetermined period of time. 7

In my invention, I provide a single overload relay for so controlling the tripping and the closing coils of an interrupter that, when an overload occurs upon the system,

the interrupter will be alternately opened and closed or the purpose of extinguishing the arc which produces the overload. I further provide means, actuated by the relay, for precluding the automatic opening and closingof the interrupter after the relay has operated a predetermined number of times.

The single figure of the accompanying Specification of Letters Patent.

have invented a 1 Patented Feb. 15, 1921.

Serial No. 117,634.

drawing is a diagrammatic view of'a distributing system that is provided with an arc-extinguishing means embodying my invention.

A generator 1 supplies energy to conductors 2 and 3 of a distributing system or circuit 4 that is provided with an interrupter 5 which is adapted to be tripped when an overload or arcing ground occurs upon the circuit 1 and to be immediately reclosed in order that the load which is connected to the circuit may not fall out of synchronism. That is, if the interrupter 5 is tripped, the voltage upon the circuit 1 is reduced substantially to zero and, it the overload is caused by an arcing ground, the arc will be extinguished because of the lack of sustaining voltage to maintain it.

The circuit interrupter 5 is provided with a trippingelectromagnet 6 and a closing electromagnet 7. A series transformer 8 is operatively connected to one conductor of the circuit 4 and is adapted to energize the winding 9 of an overload relay 10.

The overload relay 10 comprises a movable core member 11, a movable bridging contact member 12 and a pawl 13. The movable bridging contact member 12 is adapted to normally engage two stationary contact members 14: and 15 and to engage contact member 19 is adapted to become wedged between the contact members 20 and 21 in order that, each time the relay 10 is operated, the pawl 13 will engage a different tooth on the rack 18' for the purpose of moving the bridging contact member 19 further upwardly.

The contact member 21 is operatively connected to one conductor 22 ofa control circuit 23 comprising a source 24 of electrometive force. The other stationary contact member 20 is operatively connected to the stationary contact members 14 and 16 of the relay 10. The stationary contact member 17 of the relay 10 is connected to one terminal of the tripping electromagnet 6,

the other terminal or" which is operatively connected to one terminal of tie closin electromagnet 7 and to the conductor 25 o: the circuit 23.

The stationary contact member 15 oi the relay 10 is operatively connected to the stationary contact member 28 and to one terminal of the winding 28 of a definite timelimitrelay 27. The other terminal of the winding 28 is operatively connected to the terminals of the electromagnets 6 and 7 that are connected together. The other stationary contact member 29 of the relay 27 is operatively connected to the other te minal of the electromagnet 7. The relay 2? comprises the contact members 26 and 29, the winding 28, a movable magnetizable core member 30, a dash potor other time-element device 32 and a movable bridging contact member 33 that is adapted to normally engage the stationary contact members 26 and 29 and to disengage the same after current traverses the closing electromagnet 7 for a predetermined period of time.

When an overload traverses the circuit 4 after the interrupter 5 is closed, the relay 10 operates to cause its bridging contact member 12 to engage the stationary contact members 16 and 17, thereby energizing the electromagnet 6 for the purpose of tripping the interrupter 5. It will, of course, be understood that, when the movable core member 11 of the relay 10 moves upwardly, the bridging contact member 19 engages the stationary contact members 20 and 21 to thus complete the circuit from the conductor 22 of the circuit 23 through the electromagnet 6 to the other conductor 25 of the circuit 23. lVhen the interrupter 5 opens, insufficient current traverses the conductor 3 and, consequently, the winding 9. to hold the movable core member 11 in its upper position, and the bridging contact member 12 will move downwardly to engage the stationary contact members 14 and 15. \Vhen the bridging contact member 12 engages the stationary contact members 14 and 15, a circuit is completed from the conductor 22 through the contact members 26, 29 and 33 of the relay 2? and the electromagnet 7 to the conductor 25 of the circuit 23. Since the winding 28 of the relay 27 is operatively connected to the electroinagnet 7, it will be energized and, after a predetermined time. will cause its bridging contact member 33 to be disengaged from its stationary contact members 26 and 29 for the purpose of opening the circuit of the electromagnet 7, as hereinafter set forth. However, as soon as the electroinagnet 7 is energized. it will reclose the interrupter 5 and. if the are or overload continues on the circuit 4, the relay 10 will again be actuated to cause the interrupter to be tripped.

After the interrupter 5 has been opened and closed a predetermined number of times and the overload or are continues upon the circuit the bridging contact member 19 will have moved to such position as to be disengaged from the stationary contact members 20 ant. 21 to preclude the auto matic opening and closing of the interrupter 5.

If the arc has been extinguished or the overload removed from the circuit 4 after the interrupter has been closed a number of times, it is advisable to open the circuit of the electromagnet 7 in order to preventits continued energization, and, for this purpose, the relay 2? is provided. That is, after the electromagnet 7 has been energized for a predetermined period of time, the relay 27 will effect the separation of the contact members 26, 29 and 33, thereby deenergizing the electromagnet 7. A latch 34 may be provided for holding the relay 27 in its open position after it is operated until it is manually released.

I do not limit my invention to the particular arrangement illustrated, as it may be variously modified within the spirit and scope of the appended claims.

I claim as my invention:

1. In a system of distribution, the combination with a circuit interrupter and tripping and closing coils therefor, of an overload relay for energizing ,the tripping coil when an overload traverses the system and for energizing the closing coil when the circuit interrupter is opened, and means dependent upon the nuniber of times the overload relay is actuated for precluding the tripping and re-closing of the interrupter.

2. In a system of distribution, the combination with a circuit interrupter and tripping and closing coils therefor, of a relay for automatically energizing the tripping coil when an overload traverses the system and for energizing the closing coil as soon as the interrupter is opened.

3. In a system of distribution, the combination with a circuit inter? pter and tripping and closing coils therefor, or an overload relay for alternately energizing the tripping and closing coils when an overload traverses the system. i

4. In a system of distribution, the combination with a circuit interrupter and tripping and actuating electromagnets therefor, of a relay operatively connected toth system and adapted to complete the circuit of the tripping electromagnet when an arc occurs on the system and to complete the circuit of the actuating electromagnet as soon as the interrupter is tripped, and means for open circuiting the actuating electromagnet after it has been energized for a predetermined period of time.

5. In a system of distribution, the combination with a circuit interupter and tripping and actuating electromagnets therefor, of a relay responsive to an overload on the system for completing the circuit of the tripping electromagnet when the overload reaches a predetermined value and for completing the circuit of the actuating electromagnet when the overload is removed, and means actuated by the relay for open circuiting the said electromagnets after the interrupter has been opened and closed a predetermined number of times.

6. In a system of distribution, the combination with a circuit interrupter and tripping and closing coils therefor, of an overload relay for alternately energizing the tripping and closing coils when an are obtains on the system, means dependent upon the number of times the relay operates for precluding the energization of the said tripping and closing coils, and means for open circuiting the closing coil after it has been energized for a predetermined period of time.

In testimony whereof, I have hereunto subscribed my name this 19th day of Aug, 1916.

LESLIE NrCRICHTON. 

